We provide and describe a library of diffuse stellar radiation fields in spiral galaxies derived using calculations of the transfer of stellar radiation from the main morphological components - disks, thin disks, and bulges - through the dusty interstellar medium. These radiation fields are self-consistent with the solutions for the integrated panchromatic spectral energy distributions (SEDs) previously presented using the same model. Because of this, observables calculated from the radiation fields, such as gamma-ray or radio emission, can be self-consistently combined with the solutions for the ultraviolet/optical/submillimeter SEDs, thus expanding the range of applicability of the radiation transfer model to a broader range of wavelengths and physical quantities. We also give analytic solutions for radiation fields in optically thin stellar disks, in stellar disks with one dust disk and in stellar disks with two dust disks. The analytic solutions for the direct light are exact and can be used as benchmarks. The analytic solutions with scattering are only approximate, becoming exact only in the extreme optically thick limit. We find strongly contrasting solutions for the spatial distribution of the radiation fields for disks, thin disks and bulges. For bulges we find a strong dependence of the radiation fields on Sersic index.
Cosmological models predict that galaxies forming in the early Universe experience a chaotic phase of gas accretion and star formation, followed by gas ejection due to feedback processes. Galaxy bulges may assemble later via mergers or internal evolution. Here we present submillimeter observations (with spatial resolution of 700 parsecs) of ALESS 073.1, a starburst galaxy at redshift z~5, when the Universe was 1.2 billion years old. This galaxy's cold gas forms a regularly rotating disk with negligible noncircular motions. The galaxy rotation curve requires the presence of a central bulge in a…
The Bulge-Disk Decomposed Evolution of Massive Galaxies at 1<z<3 in CANDELS
本文介绍了在COSMOS和UKIDSS UDS巡天范围内,利用CANDELS WFC 3/IR成像,对红移范围为1<z 10^11 M太阳系的大质量星系的形态和光谱演化进行新的改进研究的结果<3. Our analysis is based on a bulge-disk decomposition of 396 galaxies with Mstar>。我们发现,通过模拟每个星系的H(160)图像,(Sersic指数n=4)和指数盘(n=1),我们可以锁定所有导出的凸起和盘成分的形态参数,并成功地再现较短波长的J(125),i(814),v(606)HST简单地通过浮动两个分量的幅度来成像。这就产生了细分的4波段HST测光的凸起和磁盘组件,没有额外的先验,以及描述的星系演化的分光光度模型。有了这些信息,我们就能够正确地确定星系的质量和星系的形成率,并发现:i)从z=3到z=1,星系从盘状星系为主向越来越突出的星系为主转变,但很少有星系在z=1时是纯粹的突出/椭圆星系; ii)虽然大多数被动星系是以膨胀为主,大多数恒星形成星系是以盘为主,但18+/-5%的被动星系是以盘为主,11+/-3%的恒星形成星系是以膨胀为主,这一结果需要用任何声称将恒星形成猝灭与形态转变联系起来的模型来解释; iii)存在一个小但重要的纯被动盘群体,它们通常比它们的恒星形成对应物更平坦轴比分布在b/a…
ZENS IV. Similar Morphological Changes associated with Mass- and Environment-Quenching, and the Relative importance of Bulge Growth versus the Fading of Disks
Constraints on the assembly and dynamics of galaxies. II. Properties of kiloparsec-scale clumps in rest-frame optical emission of z ~ 2 star-forming galaxies
We study the galactic bulges in the Auriga simulations, a suite of thirty cosmological magneto-hydrodynamical zoom-in simulations of late-type galaxies in Milky Way-sized dark matter haloes performed with the moving-mesh code AREPO. We aim to characterize bulge formation mechanisms in this large suite of galaxies simulated at high resolution in a fully cosmological context. The bulges of the Auriga galaxies show a large variety in their shapes,sizes and formation histories. According to observational classification criteria, such as Sersic index and degree of ordered rotation, the majority of …
We investigate the dependence of galaxy structure on a variety of galactic and environmental parameters for ~500,000 galaxies at z<0.2, taken from the Sloan Digital Sky Survey data release 7 (SDSS-DR7). We utilise bulge-to-total stellar mass ratio, (B/T)_*, as the primary indicator of galactic structure, which circumvents issues of morphological dependence on waveband. We rank galaxy and environmental parameters in terms of how predictive they are of galaxy structure, using an artificial neural network approach. We find that distance from the star forming main sequence (Delta_SFR), followed by…
We report morphological analyses of seven submillimeter galaxies (SMGs) at $z\sim2$ using the JWST NIRCam images taken as part of the public CEERS and PRIMER surveys. Through two-dimensional surface brightness profile fittings we find evidence of bulges in all the sample SMGs, in particular at F444W filter, suggesting an ubiquitous presence of stellar bulges. The median size of these bulges at F444W is found to be 0.7$\pm$1.0 kpc and its median Sersic index is 0.7$\pm$0.9. Structures akin to spiral arms and bars are also identified, although their asymmetric shapes, tidal features, as well as …